The current invention relates to liquid fuel injection methods and systems for use with diffusion flame combustors.
In diffusion flame combustors, there is a significant amount of NO.sub.x produced in the high temperature regions of flame. This is the result of NO.sub.x production being exponentially dependent on temperature. The prior art discloses injecting water or steam into the diffusion flame combustors, via an inlet separate from the fuel inlet, to decrease the peak flame temperature and lower the production of NO.sub.x.
The prior art discloses a number of problems resulting from injecting water or steam into the diffusion flame combustor. As the water or steam and fuel is injected into the combustor through different inlets, the combustion zone has uneven distributions of oil and steam resulting in locally hot and cold regions therein. The hot regions result in high NO.sub.x production and the cold regions result in high CO production, as the rate of CO oxidation to CO.sub.2 is much lower at reduced temperatures. Also, the stability of the combustion process is reduced with the injection of water or steam into the combustors due to unequal heat release from the hot and cold regions.